Osteosynthesis plate for the osteosynthesis of small neighbouring bones

Abstract

The invention relates to an osteosynthesis plate for the osteosynthesis of small neighbouring bones. The inventive osteosynthesis plate ( 1 ) is dimensioned such that it can be positioned above the bones to be treated without resting on the larger neighbouring bones. According to the invention, the osteosynthesis plate comprises lateral holes ( 16 ) for the insertion of screws ( 6 ) which are used to fix same to the bones ( 2 to 5 ). The plate is characterised in that: (i) it comprises a flat face ( 10 ) which is intended to come into contact with the bones to be treated; and (ii) it comprises holes ( 16 ) for receiving screws ( 6 ), which have axes that are inclined in relation to the aforementioned flat face ( 10 ) and which are designed such that the inserted screws diverge towards the outside of the plate ( 1 ).

1 . Osteosynthesis plate for osteosynthesis of small neighbouring bones, in particular wrist bones, having dimensions such that it may be placed above the bones to be treated, without resting on larger neighbouring bones, and comprising lateral holes for inserting screws to fix the latter to such bones characterized in that it comprises a face intended to come into contact with the bones to be treated which is flat, and comprises holes for receiving screws having axes that are tilted in relation to said flat face, such holes being designed such that the screws, once inserted into said holes, diverge towards the outside of the plate.  
   
   
       2 . Osteosynthesis plate according to  claim 1 , characterized in that it is circular in shape.  
   
   
       3 . Osteosynthesis plate according to  claim 1 , characterized in that its face opposite to that coming into contact with the bones to be treated exhibits a recess enabling to lower the heads of the screws with respect to the plate in implanting position thereof.  
   
   
       4 . Osteosynthesis plate according to  claim 3 , characterized in that the recess occupies the major portion of said face of the plate opposite to that coming into contact with the bones to be treated, and is in the form of a hollow spherical cap.  
   
   
       5 . Osteosynthesis plate according to  claim 1 , characterized in that at least one screw hole is in the form of a hollow spherical section, and in that the head of at least one screw exhibits a side wall in the form of matching spherical section, these respective shapes of the hole and of the screw head enabling multidirectional orientation of the screw with respect to the plate.  
   
   
       6 . Osteosynthesis plate according to  claim 1 , characterized in that it comprises a number of screw holes equal to the number of bones to be treated, or close to such number, in particular four holes to perform, when dealing with wrist bones, osteosynthesis of the bone capitatum, of the semi-lunar bone, of the cuneiform bone and of the unciform bone.  
   
   
       7 . Osteosynthesis plate according to  claim 1 , characterized in that it comprises a central hole of diameter adjusted to that of a positioning spindle, enabling the sliding engagement of the plate on said spindle, and a mark situated at the periphery thereof.  
   
   
       8 . Set of instruments for the insertion of the osteosynthesis plate according to  claim 1 , characterized in that it comprises a reamer.  
   
   
       9 . Set of instruments according to  claim 8 , characterized in that it comprises a positioning spindle, enabling the sliding engagement of the plate on said spindle.  
   
   
       10 . Set of instruments according to  claim 8 , characterized in that it comprises a dummy of the plate, i.e. a test piece identical in shape to that of the plate, provided with a mark identical to that of the plate.  
   
   
       11 . Set of instruments according to  claim 10 , characterized in that the dummy provides with a hole identical to that of the plate, enabling to engage this dummy on said positioning spindle.  
   
   
       12 . Set of instruments according to  claim 9 , characterized in that the reamer is hollowed and may be engaged by sliding, but with a tight fit, on said positioning spindle.  
   
   
       13 . Set of instruments for the insertion of the osteosynthesis plate according to  claim 2 , characterized in that it comprises a reamer.  
   
   
       14 . Set of instruments for the insertion of the osteosynthesis plate according to  claim 3 , characterized in that it comprises a reamer.  
   
   
       15 . Set of instruments for the insertion of the osteosynthesis plate according to  claim 4 , characterized in that it comprises a reamer.  
   
   
       16 . Set of instruments for the insertion of the osteosynthesis plate according to  claim 5 , characterized in that it comprises a reamer.  
   
   
       17 . Set of instruments for the insertion of the osteosynthesis plate according to  claim 6 , characterized in that it comprises a reamer.  
   
   
       18 . Set of instruments for the insertion of the osteosynthesis plate according to  claim 7 , characterized in that it comprises a reamer.